Solubility of amphotericin B in water-lecithin-dispersions and lecithin-based submicron emulsions.

The aim of this work was to evaluate water-lecithin-dispersions (WLDs) as carriers for amphotericin B (AmB) and to compare the drug solubility in WLDs and O/W lecithin-based submicron emulsions (SMEs) in order to evaluate the influence of lecithin content on the dosage form solubilization of the active compound. WLDs and different SMEs with either 1.2 or 2.4% of lecithin were prepared. WLD with 2.4% lecithin show a 10-fold increase in solubilization of AmB compared with 1.2% lecithin WLD. SMEs with 1.2% lecithin show an increase of over 400 times in solubilization compared with WLD containing the same concentration of lecithin, whereas SMEs with 2.4% lecithin show an increase of over 40 times compared with the corresponding WLD. Drug solubilization in SMEs with 2.4% lecithin is not significantly greater than in those containing 1.2% lecithin. The content of surfactant Brij 97 ® had a significant influence on drug solubilization in SMEs (P < 0.05). Results indicate that indicate that SMEs are proper systems to solubilize AmB. It can be assumed that solubilization is due to the formulation microstructure and not to the separate components themselves.